Effect Of Unilateral Chewing On The Expression Of Estrogen Receptor Alpha In Rat Condylar Cartilage

[Abstract] Objective:To investigate the expression of estrogen receptor-a (ERa) i temporomandibular joints(TMJs) of Sprague-Dawley rats. Methods:8-week-old SD rat were randomly divided into experimental and control groups with equal numbe distribution. In experimental group, through extracting the side of maxillary molars, w build rats unilateral chewing model, and then we draw materials in 2,4,6 and 8 week after the operation. The expression of estrogen receptors were detected by SAB(?) technique of immunocytochemistry, and then were analyzed by the density c estrogen-positive chondrocytes. Results:1) The ERa was abundant in the hypertrophi layer of rat condylar cartilage; 2) In control group, the expression of ERa decrease gradually from 10-week-old to 16-week-old; 3) At 2 weeks after unilateral chewin operation, the expression of ERa in extraction side of experimental group was lower tha non-extraction side (P<0.05), while the expression of ERa was no difference betwee extraction side and non-extraction side (P> 0.05) at 4,6,8 weeks; 4) At 2,4 weeks afte unilateral chewing operation, the expression of ERa in experimental group was higher tha(?) control group (P<0.05), while the expression of ERa in experimental group was lowe than the control group (P<0.05) at 4,6 weeks. Conclusion:ERa play an important role i(?) the reconstruction of condylar cartilage of rats induced by unilateral chewing.